Chemoprevention of DMBA-induced UV-B promoted, NOR-1-induced TPA promoted skin carcinogenesis, and DEN-induced phenobarbital promoted liver tumors in mice by extract of beetroot.
ABSTRACT Our previous studies identified the extract of Beta vulgaris (beetroot), commercially also known as betanin, as a potent cancer chemopreventive agent in both in vitro Epstein-Barr early antigen activation assay and in an in vivo two-stage mouse lung and skin carcinogenesis. To explore this issue further, we have now investigated its cancer chemopreventive potentials in three different chemical carcinogen initiation-promotion experimental tumor models in mice. Following tumor initiation with 390 nmol of 7,12-dimethylbenz(a)anthracene (DMBA) in 100 microl of acetone, the mouse skin tumor promotion with 3430 J/m(2) of ultraviolet light-B (UV-B) as well as splenomegaly was significantly inhibited by oral administration of 0.0025% betanin. At the same dose, betanin also afforded significant protection in the mouse skin cancer model following the topical application of 390 nmol of (+/-)-(E)-4-methyl-2-[(E)-hydroxyamino]-5-nitro-6-methoxy-3-hexanamide (NOR-1) in 100 microl of acetone and promoted by topical administration of 1.7 nmol of 12-O-tetradecanoylphorbol-13-acetate (TPA). In the two-stage model of hepatocarcinogenesis in mice with N-nitrosodiethylamine (DEN, 30 mg/kg) as the initiator and phenobarbital as the promoter, oral administration of 0.0025% betanin also showed a very significant inhibition of both the incidence and multiplicity of the liver tumors. These findings along with our initial reports suggest that betanin which is a regularly consumed natural product colorant is an effective cancer chemopreventive agent in mice. The most interesting observation is that the cancer chemopreventive effect was exhibited at a very low dose used in the study and thus indicating that beetroot warrants more attention for possible human applications in the control of malignancy.
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ABSTRACT: The aim of the study was to investigate the effects of beetroot juice fermented by Lactobacillus brevis 0944 and Lactobacillus paracasei 0920 (FBJ) on carcinogen induction of aberrant crypt foci (ACF) in rat colon. 2-Amino-1-methyl-6-phenylimidazo[4,5-b] pyridine (PhIP) was used as carcinogen, which was administrated intragastrically at a dose of 10μg/day, every day of the experiment. Additionally, we investigated the cytotoxicity and genotoxicity of fecal water from experimental animals in the Caco-2 cell line, evaluated by MTT test and the comet assay, respectively, as well as by the count of bacteria adhered to colon epithelium assessed by fluorescence in situ hybridization. Oxidative stress in rats was expressed by measuring serum antioxidant status and the level of malondialdehyde in the kidneys and liver. The experimental rats were divided into four groups based on diet type: basal diet, basal diet supplemented with FBJ, basal diet and PhIP treatment, and basal diet supplemented with FBJ and PhIP treatment. FBJ significantly reduced the number of ACF in PhIP-treated rats (from 59±18 to 26±4). Moreover, the number of extensive aberrations (more than 4 crypts in a focus) decreased from 52±18 to 18±4. Fecal water obtained from rats fed with a PhIP-containing diet induced pronounced cytotoxic and genotoxic effects in Caco-2 cells, but FBJ supplementation of the diet abolished these effects. In groups fed dietary PhP and FBJ the latter was found to increase the antioxidant status of serum from 40% to 66% depending on the fraction. Reduced concentration of malondialdehyde was found only in the kidneys of rats fed with PhIP and FBJ. FBJ present in the diet of rats causes a reduction of MDA in the kidneys from 118.7nmol/g tissue to 100nmol/g tissue. The presence of FBJ in the diet of rats significantly increased the count of bacteria, including Lactobacillus/Enterococcus and Bacteroides-Prevotella group adhered to colonic epithelium. In conclusion, supplementation of the diet with lactofermented beetroot juice may provide protection against precancerous aberrant crypt formation and reduce the cytotoxic and genotoxic effects of fecal water and improve the oxidative status of the organism.09/2012; 34(3). DOI:10.1016/j.etap.2012.08.009
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ABSTRACT: The aim of this study was to evaluate the effect of betanin, one of the beetroot major components, on ROS production, DNA damage and apoptosis in human resting and stimulated with phorbol 12-myristate13-acetate polymorphonuclear neutrophils, one of the key elements of the inflammatory response. Incubation of neutrophils with betanin in the concentration range 2-500 µM resulted in significant inhibition of ROS production (by 15-46%, depending on the ROS detection assay). The antioxidant capacity of betanin was most prominently expressed in the chemiluminescence measurements. This compound decreased also the percentage of DNA in comet tails in stimulated neutrophils, but only at the 24 h time point. In resting neutrophils an increased level of DNA in comet tails was observed. Betanin did not affect the activity of caspase-3, in resting neutrophils, but significantly enhanced the enzyme activity in stimulated neutrophils. The western blot analysis showed, however, an increased level of caspase-3 cleavage products as a result of betanin treatment both in resting and stimulated neutrophils. The results indicate that betanin may be responsible for the effect of beetroot products on neutrophil oxidative metabolism and its consequences, DNA damage and apoptosis. The dose and time dependent effects on these processes require further studies.Phytotherapy Research 06/2012; 26(6):845-52. DOI:10.1002/ptr.3649 · 2.40 Impact Factor
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ABSTRACT: The ploidy levels of the cells in different organs (leaves, petioles and roots) of red beet (Beta vulgaris L.) plants of different ages, as well as of different in vitro systems (transformed hairy roots, calli derived from leaves and rhizogenic calli), were investigated using flow cytometry. Two callus lines with red and yellow phenotypes, derived by mechanical separation of the morphologically heterogeneous rhizogenic callus, were also examined. All investigated samples experienced several cycles of endoreduplication. The older organs exhibited higher levels of polysomaty than the young ones. The highest degree of endoreduplication was found in old petiole tissue and the lowest in the red callus line (cycle values of 1.81 and 0.55, respectively). Interestingly, the callus derived from leaves did not exhibit a 2Cx peak, but was tetraploid, probably due to genetic instability, which may have been caused by prolonged cultivation under in vitro conditions. Red and yellow calli showed significantly lower polysomaty (cycle values of 0.55 and 0.59, respectively) than the primary rhizogenic callus (cycle value of 1.09). The DNA profiles of the two phenotypes differed, possibly reflecting differences in their metabolism.Engineering in Life Sciences 02/2010; 10(2):139 - 147. DOI:10.1002/elsc.200900021 · 1.89 Impact Factor